Compressor drive and fuel supply for gas turbine power plants



Jan. 12, 1954 P. P. NEWCOMB 2,665,549 COMPRESSOR DRIVE AND FUEL SUPPLY FOR GAS TURBINE POWER PLANTS Filed Nov. 2. 1949 x NR INVEN TOR. P552329 1. NewcomZ @220 a -ney Patented Jan. 12, 1954 COMPRESSOR DRIVE AND FUEL SUPPLY FOR GAS TURBINE POWER PLANTS Philip P. Newcomb, Manchester,

to United Aircraft Corporation,

Conn., assignor East Hartford,

Conn., a corporation of Delaware Application November 2, 1949, Serial No. 125,064

9 Claims.

The present invention relates to a multistage compressor for a gas turbine power plant in which at least the last stage of the compressor rotor is driven at a diiferent speed from certain of the other stages.

It is well known that multistage axial flow compressors operate at best eificiency, especially where there is a relatively large number of stages, if all of the stages are not rotated at the same speed. A feature of the present invention is the division of the compressor rotor into two or more groups of stages with an arrangement for driving the last group at a speed different from the adjacent group but from the same driving shaft that operates the adjacent group of stages. Another feature is the drive of the last group or one group of stages as a function of the fuel quantity supplied to the combustion chamber of the gas turbine power plant.

One of the features of the invention is the drive of the last stage of the compressor or in some cases the last group of stages through a fluid coupling and the delivery of fuel to the power plant through this coupling so that the speed of the compressor stage driven through the coupling is varied as a function of the quantity of fuel supplied to the power plant. Another feature is the variationin the pressure of the fuel supplied to the power plant as a function of the fuel quantity delivered thereto.

Other obiects and advantages will be apparent from the specification and claims, and from the accompanying drawing which illustrates an embodiment of the invention.

-'I'he single figure is a sectional view through a part of the gas turbine power plant.

The entire power plant is not shown since the invention can he described in connection with the essential operating parts of the power plant. These include a multistage compressor 2 of the axial flow type which includes a stator 4 having spaced rows of inwardly projecting vanes 6 alternating with correspondingly spaced rows of blades 8 on a compressor rotor 29. This rotor which may be supported as by a bearing 12 carried by a support I4 adjacent the inlet [6 for the compressor is connected as by the shaft E8 to the turbine rotor 26. The latter has a row of blades 22 at its periphery downstream of the turbine nozzle vanes 24 carried by the turbine casing 26.

The compressor and turbine casings are interconnected by a burner casing 28 which in con junction with an inner duct 30 defines an annular combustion chamber 32 between the discharge end of the compressor and the turbine nozzles. Within the combustion chamber 30 are inner and outer shields 34 and 36 which define between them an annular flame duct in which combustion takes place.

The compressor rotor l0 in the arrangement shown is divided into separate groups of stages of which the last stage 38 forms one group and the remainder of the compressor forms the other group of stages. It will be obvious that under certain conditions either of the group-s may consist of a greater or less number of stages depending on the specific compressor design. The last part of the compressor rotor, that is, the last stage 38, is driven from the same drive shaft !8 that drives the remainder of the rotor but is driven at a different speed through a fluid coupling 40, the runner 42 of which is connected to the shaft l8 to rotate therewith. The impeller 44 of the coupling has mounted thereon the last compressor stage 38 and the runner is supported for rotation independently of the shaft 18 as by a bearing 46 which supports the downstream end of the adjacent group of stages and also by a bearing element 48 mounted on the shaft l8. Fuel is admitted into the end of the shaft I8 which is hollow through a fuel supply line 49 to provide for the flow of fuel to the inlet passage 50 provided in the shaft for the flow of fuel into the fluid coupling. The outlet for the coupling is through a number of passages 52 angularly spaced around the compressor disk 54 forming a part of the last compressor stage and this passage connects with a number of fuel tubes and nozzles 56 only one ofwhich is shown. These nozzles 56 which rotate withdisk 54 connect with the passages 52 and discharge fuel into the inlet end of the flame duct defined by the shields 34 and 36. The fuel supply may be controlled by a valve 53.

At low fuel flows the coupling is only partially filled with fuel and the slip between the runner and impeller is high so that the last com pressor stage rotates relatively slowly. This being the case the centrifugal force on the fuel in the coupling and in the passages 52 is relatively low so that the flow of fuel through the passages and into the fuel nozzles is at a. low pressure and is equal in quantity to the fuel supplied to the coupling. As the quantity of fuel pling fills up to a greater amount thereby decreasing the slip and increasing the speed of the last compressor stage. This higher speed in turn increases the centrifugal force and. the pressure on the fuel within the passage 52 thereby increasing the rate of flow so that it will again compare with the fuel flow into the coupling. Thus it is apparent that the speed of the last compressor stage or the last group of stages driven by the coupling is proportional to the fuel flow to the power plant and the pressure of fuel at the nozzles 56 is also proportional to the fuel flow. I

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims.

I claim:

1. In a gas turbine power plant, a multistage compressor with the stages arranged in two independently rotatin groups, a fluid couplng connecting one of said groups to the adjacent group, a turbineconnected to said adjacent group for driving it, a combustion chamber through which gas from the compressor is delivered to the turbine, means for supplying fuel to said power plant, and a connection for directing the supplied fuel through said coupling as the coupling fluid to said combustion chamber.

2. In a gas turbine power plant, a multistage compressor with the stages arranged in two independently rotatin groups, the last compressor stage forming at least a part of one group, a fluid coupling connecting said one group to the adjacent group, a turbine connected to said adjacent group for driving it, a combustion cham-- her through which gas from the compressor is delivered to the turbine, means for supplying fuel to said power plant, and a connection for directing the supplied fuel through said coupling as the coupling fluid to said combustion chamber.

3. In a gas turbine power plant, a multistage compressor with the stages arranged in two independently rotating groups, the last compressor stage forming at least a part of one group, a fluid coupling connecting said one group to the adjacent group, a turbine connected to said ad- .iacent group for driving it, a combustion chamber through which gas from the compressor is delivered to the turbine, means for supplying fuel to said power plant, and a connection for directing the supplied fuel through said coupling as the coupling fluid to said combustion chamber, said one group having a series of fuel nozzles mounted thereon for discharging fuel from the coupling into the airstream from the compressor.

4. In a gas turbine power plant, a multistage compressor with the stages arranged in two independently rotating groups with the last compressor stage forming at least a part of one group, a turbine, a connection from said turbine to the other group of stages for driving it, a combustion chamber into which air from the compressor is delivered, means including a series of nozzles for delivering fuel to said combustion chamber, means for supplyin fuel to said n"zales, means for adjusting the rate of fuel supply, and means forming a driving connection between said other group and the turbine, said last means being a part of the path for fuel from the supply to. the nozzle and being rendered operative by the flow of fuel to the combustion chamber and being effective in proportion to the quantity of fuel supplied for rotating said one group at a speed proportional to the quantity of fuel supplied.

5. In a gas turbine power plant, a multistage compressor with the stages arranged in two independently rotating groups with the last compressor stage formin at least part of one group, p

a turbine, a connection from said turbine to the other group for driving it, a combustion chamber into which air from the compressor is delivered, means including a series of nozzles for supplying fuel to said combustion chamber, means for adjusting the rate of fuel supply, means including a fluid coupling between said turbine and said one group for rotating said one group, and means for directingthe fuel through the coupling as the coupling fluid such that said one group is rotated at a speed proportional to the quantity of fuel supplied, said one group having mounted thereon the series of fuel nozzles for the discharge of the fuel from the coupling into the airstream from the compressor.

6. In a gas turbine power plant, a multistage compressor with the stages arranged in two independently rotating groups and with the last stage forming at least a part of one group, a turbine driven by gas from the compressor, a connection from said turbine to the other group for driving it, a combustion chamber through which gas from the compressor is delivered to the turbine, means including a series of nozzles for delivering fuel to said combustion chamber, means for supplying fuel to said nozzles, means for adjusting the rate of fuel supply, and means forming a driving connection between said groups, said last means being a part of the path for fuel from the supply to the nozzle and being rendered operative by the flow of fuel to the combustion chamber and being effective in proportion to the quantity of fuel supplied to the combustion chamber for rotating said one group at a speed proportional to the quantity of fuel supplied.

'7. In a gas turbine power plant, a multistage compressor with the stages arranged in two independently rotating groups and with the last stage forming at least a part of one group, a turbine driven by gas from the compressor, a connection from said turbine to the other group for driving it, a combustion chamber through which gas from the compressor is delivered to the turbine, means including a series of nozzles for deliverin fuel to said combustion chamber, means for supplying fuel to said nozzles, means for adjusting the rate of fuel supply, and means forming a drivin connection between said groups, said last means being a part of the path for fuel from the supply to the nozzle and being rendered operative by the flow of fuel to the combustion chamber and being effective in proportion to the quantity of fuel supplied to the combustion chamber for rotating said one group at a speed proportional to the quantity of fuel supplied, said one group having the series of fuel nozzles mounted thereon and located downstream of the compressor for discharging the fuel into the airstream.

B. In a gas turbine power plant, a multistage compressor with the last stage thereof rotatable independently of the remaining stages, a fluid coupling connecting said last stage to the remaining stages, a turbine connected to and drivmg said remaining stages, a combustion chamber through which air from the compressor is delivered to the turbine, means for supplying fuel to the combustion chamber, and a connection for said fuel supply for directing the fuel as the combustion chamber, said last compressor stage having mounted thereon fuel nozzles with the end thereof located in the airstream for dischargin the fuel from the fluid coupling into the airstream.

PHILIP P. NEWCOMB.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Lysholm Sept. 26, 1944 Number 

